Treatment for coronavirus infection and associated cytokine toxicity

ABSTRACT

The present invention relates to novel methods for treating or preventing coronavirus infection and cytokine-associated toxicity, including cytokine toxicity resulting from aberrant activation of the immune system in coronavirus disease or infection, such as those from SARS-CoV-2.

RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.17/910,220, filed on Sep. 8, 2022, which is a U.S. National StageApplication filed under 35 U.S.C. § 371(c), based on InternationalPatent Application No. PCT/AU2021/050215, filed on Mar. 12, 2021, whichclaims priority to and the benefit of the filing dates of AustralianPatent Application Nos. 2020900751, filed on Mar. 12, 2020, and2020904824, filed on Dec. 23, 2020, the entire contents of each of theabove-referenced applications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to novel methods for treating orpreventing coronavirus infection and cytokine-associated toxicity,including cytokine toxicity resulting from aberrant activation of theimmune system in coronavirus disease or infection, such as those fromSARS-CoV-2.

BACKGROUND OF THE INVENTION

Coronaviruses are a group of viruses that cause diseases in mammals andbirds. In humans, coronaviruses cause respiratory tract infections thatare typically mild, such as some cases of the common cold (among otherpossible causes, predominantly rhinoviruses), though rarer forms can belethal, such as SARS, MERS, and SARS-CoV-2. Symptoms vary in otherspecies: in chickens, they cause an upper respiratory tract disease,while in cows and pigs they cause diarrhoea. There are yet to bevaccines or antiviral drugs to prevent or treat human coronavirusinfections.

Coronaviruses constitute the subfamily Orthocoronavirinae, in the familyCoronaviridae, order Nidovirales, and realm Riboviria. They areenveloped viruses with a positive-sense single-stranded RNA genome and anucleocapsid of helical symmetry. The genome size of coronavirusesranges from approximately 27 to 34 kilobases, the largest among knownRNA viruses.

In 2020, the world faced an extreme situation of a highly infectiouscoronavirus (2019-nCoV; SARS-CoV-2) manifesting as a disease termed“COVID-19”. SARS-CoV-2 infections globally have exceeded 100 millionconfirmed cases with more than 2 million deaths to date, across morethan 200 countries, areas or territories. COVID-19 manifestations rangefrom mild to severe life-threatening with a substantial mortality rate.

It is likely that Angiotensin Converting Enzyme 2 (ACE2) is the receptortarget for SARS-CoV-2. ACE2 is an exopeptidase that catalyses theconversion of angiotensin I to the nonapeptide angiotensin or theconversion of angiotensin II to angiotensin. ACE2 has a broad expressionprofile, being expressed in nearly all human organs to varying degrees.In the respiratory system, ACE2 is mainly expressed on type II alveolarepithelial cells, but is also expressed at lower levels in the oral andnasal mucosa and nasopharynx. ACE2 is also highly expressed onmyocardial cells, proximal tubule cells of the kidney, bladderurothelial cells and is abundantly expressed on the enterocytes of thesmall intestine, especially in the ileum. Consequently, there aremultiple sites for potential entry of the SARS-CoV-2 virus

Given that the receptor target of SARS-CoV-2 is expressed in multipledifferent tissue types, COVID-19 disease has been shown to manifest withsymptoms that include the intestinal and vascular systems, in additionto the respiratory system. As the disease progresses or worsens, therisk of aberrant inflammation and cytokine storm increases.

Cytokine-associated toxicity, also known as cytokine release syndrome(CRS), is a non-antigen specific toxicity that occurs as a result ofhigh-level immune activation. CRS manifests when large numbers oflymphocytes and/or myeloid cells become activated and releaseinflammatory cytokines. The result is a potentially fatal immunereaction consisting of a positive feedback loop between cytokines andlymphocytes. In severe cases, the CRS is referred to as a ‘cytokinestorm’, and can occur as a result of coronavirus infection.

Cytokine-associated toxicity has been reported occur in response to avariety of infectious and non-infectious diseases including graft versushost disease (GVHD), acute respiratory distress syndrome (ARDS), sepsis,Ebola, avian influenza, smallpox, and systemic inflammatory responsesyndrome (SIRS).

There is a need for new or improved treatments for coronavirusinfections and/or conditions associated with, or caused by,coronaviruses. Reference to any prior art in the specification is not anacknowledgment or suggestion that this prior art forms part of thecommon general knowledge in any jurisdiction or that this prior artcould reasonably be expected to be understood, regarded as relevant,and/or combined with other pieces of prior art by a skilled person inthe art.

SUMMARY OF THE INVENTION

In a first aspect, the present invention provides a method of treatingor preventing a coronavirus infection, comprising:

-   -   providing a subject who is suspected of having or at risk of        developing a coronavirus infection,    -   administering to the subject, a therapeutically effective amount        of sulfated polysaccharide or a pharmaceutically acceptable salt        thereof,

thereby treating or preventing coronavirus infection in the subject.

In a further aspect, the present invention provides a method forreducing the severity of a coronavirus infection, the method comprisingadministering to a subject in need thereof, a therapeutically effectiveamount of sulfated polysaccharide or a pharmaceutically acceptable saltthereof, thereby reducing the severity of the coronavirus infection inthe subject. Preferably the coronavirus infection is an infection with abeta-coronavirus, more preferably an infection with a beta-coronavirusfrom Lineage B, such as an infection with SARS-CoV or an infection withSARS-CoV-2. More preferably, the infection is an infection withSARS-CoV-2 or a mutated form or variant thereof, including but notlimited to mutants D614G, S477N, 20A.EU1, the Danish COVID-19 minkvariant, the “UK” variant B 1. 1. 7, the “South African” variant B. 1.351, the “Brazil” variant P.1 or the “Russian” variant B. 1. 1. 317.

In another aspect, the present invention provides a method of treatingand/or preventing a disease associated with, or caused by, acoronavirus, the method comprising administering to a subject in needthereof a therapeutically effective amount of sulfated polysaccharide ora pharmaceutically acceptable salt thereof, thereby treating and/orpreventing a disease associated with, or caused by, a coronavirus.

Preferably the disease is associated or caused by a beta-coronavirus,more preferably a beta-coronavirus from Lineage B, such as SARS-CoV orSARS-CoV-2. Most preferably, the disease is associated or caused bySARS-CoV-2 or a mutated form or variant thereof, including but notlimited to mutants D614G, S477N, 20A.EU1, or the Danish COVID-19 minkvariant. Alternatively, the disease is associated or caused by abeta-coronavirus from Lineage C, optionally MERS-CoV.

The disease associated with or caused by the coronavirus infection maybe a respiratory disease, an inflammatory disease (includingcytokine-associated toxicity), a cardiovascular disease or agastrointestinal disease.

Accordingly, in another aspect, the present invention provides a methodof treating and/or preventing a respiratory disease or conditionassociated with a coronavirus infection, the method comprisingadministering to a subject in need thereof, a therapeutically effectiveamount of sulfated polysaccharide or a pharmaceutically acceptable saltthereof, thereby treating and/or preventing a respiratory disease orcondition associated with a coronavirus infection. Preferably therespiratory disease or condition is associated with a beta-coronavirus,more preferably a beta-coronavirus from Lineage B, such as SARS-CoV orSARS-CoV-2. Most preferably, the respiratory disease or condition isassociated or caused by SARS-CoV-2 or a mutated form or variant thereof,including but not limited to mutants D614G, S477N, 20A.EU1, the DanishCOVID-19 mink variant, the “UK” variant B 1. 1. 7, the “South African”variant B. 1. 351, the “Brazil” variant P.1 or the “Russian” variantB. 1. 1. 317.

In this aspect, the respiratory disease or condition may comprise airwayinflammation and the method thereby reduces airway inflammation in thesubject or improves the ability of the subject to control a respiratorydisease or condition during a coronavirus infection.

Further, the present method provides a method of treating or preventingcytokine-associated toxicity caused by or associated with a coronavirusinfection, the method comprising:

-   -   providing a subject who is suspected of having coronavirus        infection and is at risk of developing or has developed        cytokine-associated toxicity,    -   administering to the subject, a therapeutically effective amount        of a sulfated polysaccharide or a pharmaceutically acceptable        salt thereof,

thereby treating or preventing cytokine-associated toxicity in thesubject. Preferably, the cytokine-associated toxicity is associated orcaused by a beta-coronavirus, more preferably a beta-coronavirus fromLineage B, such as SARS-CoV or SARS-CoV-2. Most preferably, the diseaseis associated or caused by SARS-CoV-2 or a mutated form or variantthereof, including but not limited to mutants D614G, S477N, 20A.EU1, orthe Danish COVID-19 mink variant. Alternatively, the disease isassociated or caused by a beta-coronavirus from Lineage C, optionallyMERS-CoV.

In any aspect, treatment of a coronavirus disease comprises treating oneor more symptoms associated with infection with a coronavirus or with adisease associated with or caused by coronavirus infection. Accordingly,in still a further aspect, the present invention relates to a method oftreating one or more of fever, hypotension, tachycardia, myalgia,headache, vascular inflammation, gastrointestinal inflammation anddysfunction, or inappropriate cytokine release, caused by or associatedwith a coronavirus infection, the method comprising:

-   -   providing a subject who has or is suspected of having a        coronavirus infection, and wherein the individual has or is        suspected of having fever, hypotension, tachycardia, myalgia,        headache, vascular inflammation, gastrointestinal inflammation        and dysfunction, or inappropriate cytokine release induced by        the coronavirus,    -   administering to the individual, a therapeutically effective        amount of sulfated polysaccharide or pharmaceutically acceptable        salt thereof,

thereby treating one or more of fever, hypotension, tachycardia,myalgia, headache, vascular inflammation, gastrointestinal inflammationand dysfunction, or inappropriate cytokine release induced bycoronavirus infection. Preferably, the coronavirus infection is aninfection with a beta-coronavirus, preferably from an infection with abeta-coronavirus from Lineage B, such as an infection with SARS-CoV oran infection with SARS-CoV-2. Preferably, the coronavirus infection is aSARS-CoV-2 infection, or an infection with a mutated form or variantthereof, including but not limited to mutants D614G, S477N, 20A.EU1, orthe Danish COVID-19 mink variant.

In a further aspect, the present invention provides a method of treatingcytokine-associated toxicity induced by acute respiratory distresssyndrome (ARDS), sepsis, systemic inflammatory response syndrome (SIRS),severe viral infection, pneumonia severe acute respiratory syndrome(SARS), comprising:

-   -   providing an individual who is suspected of having        cytokine-associated toxicity induced by acute respiratory        distress syndrome (ARDS), sepsis, systemic inflammatory response        syndrome (SIRS), severe viral infection, pneumonia severe acute        respiratory syndrome (SARS),    -   administering to the individual, an amount of sulfated        polysaccharide or a pharmaceutically acceptable salt thereof        effective to treat the cytokine-associated toxicity,

wherein the sulfated polysaccharide is selected from the groupconsisting of pentosan polysulfate, chondroitin sulfate A, chondroitinsulfate B, chondroitin sulfate C, keratan sulfate, heparin, heparansulfate, dextran polysulfate, fucoidan, lentinan sulfate, mannansulfate, galactan sulfate, xylomannan sulfate, rhamnan sulfate, curdlansulfate, or sulfated fucan, and pharmaceutically acceptable saltsthereof,

thereby treating cytokine-associated toxicity in the individual.

The invention also relates to a method of preventing one or more offever, hypotension, tachycardia, myalgia, headache or inappropriatecytokine release induced by coronavirus infection, including

-   -   providing a subject who is exposed to coronavirus infection, and        wherein the subject is at risk of developing fever, hypotension,        tachycardia, myalgia, headache or inappropriate cytokine release        induced by the exposure,    -   administering to the subject, an amount of sulfated        polysaccharide or pharmaceutically acceptable salt thereof,        effective to prevent one or more of fever, hypotension,        tachycardia, myalgia, headache or inappropriate cytokine        release,

thereby preventing fever, hypotension, tachycardia, myalgia, headache orinappropriate cytokine release induced by coronavirus exposure.

It will be appreciated that the methods of the invention extend to thetreatment or prevention of a range of disease severity. In certainembodiments, the symptoms are mild such that the subject can be treatedat home. In other embodiments, the symptoms are more severe, requiringhospitalisation, or even intensive care unit treatment.

In further aspects of the invention, there is provided a method forpreventing or reducing the likelihood of infection (including of severeinfection) with a coronavirus. The methods comprise administering asulfated polysaccharide as described herein, to a subject considered atrisk of, or known to be exposed to coronavirus. Examples of subjects whomay be at risk of exposure and infection include subjects who areimmunocompromised (including a subject who has primary or secondaryimmunodeficiency), an adult more than 60 years of age, a child youngerthan 2 years of age, healthcare workers, adults or children in closecontact with a person(s) with confirmed or suspected coronavirusinfection, and people with underlying medical conditions such aspulmonary infection, heart disease, obesity or diabetes.

The methods of the present invention are also useful for reducing viralload in individuals who are asymptomatic, and thereby reduce thelikelihood of the individual spreading the infection to otherindividuals. Non-symptomatic individuals may be identified via faecal,nasal and/or pharangeal swabs which indicate a presence of coronavirusinfection.

In any aspect described herein, the sulfated polysaccharide is selectedfrom the group consisting of: pentosan polysulfate, chondroitin sulfateA, chondroitin sulfate B, chondroitin sulfate C, keratan sulfate,heparin, heparan sulfate, dextran polysulfate, fucoidan, lentinansulfate, mannan sulfate, galactan sulfate, xylomannan sulfate, rhamnansulfate, curdlan sulfate, or sulfated fucan and pharmaceuticallyacceptable salts thereof.

In particularly preferred aspects of the present invention, thesulphated polysaccharide is pentosan polysulfate, or a pharmaceuticallyacceptable salt thereof.

In any embodiment of the invention, the sulfated polysaccharide,preferably pentosan polysulfate (PPS) is administered to the individualintravenously, subcutaneously, orally, intramuscularly, via gastrictube, intranasally or by inhalation.

The present invention also provides for the use of a sulfatedpolysaccharide, or a pharmaceutically acceptable salt thereof, in themanufacture of a medicament for:

-   -   treating or preventing a coronavirus infection;    -   reducing the severity of a coronavirus infection;    -   treating and/or preventing a disease associated with, or caused        by, a coronavirus infection;    -   treating or preventing a respiratory disease, an inflammatory        disease (including cytokine-associated toxicity), a        cardiovascular disease or a gastrointestinal disease caused by        or associated with a coronavirus infection;    -   treating or preventing cytokine-associated toxicity caused by or        associated with a coronavirus infection; and/or    -   treating or preventing one or more of fever, hypotension,        tachycardia, myalgia, headache or inappropriate cytokine release        induced by coronavirus infection.

In any use described herein, the sulfated polysaccharide is optionallyselected from the group consisting of: pentosan polysulfate, chondroitinsulfate A, chondroitin sulfate B, chondroitin sulfate C, keratansulfate, heparin, heparan sulfate, dextran polysulfate, fucoidan,lentinan sulfate, mannan sulfate, galactan sulfate, xylomannan sulfate,rhamnan sulfate, curdlan sulfate, or sulfated fucan and pharmaceuticallyacceptable salts thereof. Preferably, the sulphated polysaccharide ispentosan polysulfate, or a pharmaceutically acceptable salt thereof.

In any use described herein, the coronavirus infection is an infectionwith a beta-coronavirus, preferably from an infection with abeta-coronavirus from Lineage B, such as an infection with SARS-CoV oran infection with SARS-CoV-2. Preferably, the coronavirus infection is aSARS-CoV-2 infection, or an infection with a mutated form or variantthereof, including but not limited to mutants D614G, S477N, 20A.EU1, orthe Danish COVID-19 mink variant.

The present invention also provides for a sulfated polysaccharide,preferably pentosan polysulfate, or a pharmaceutically acceptable saltthereof, or a pharmaceutical composition comprising a sulphatedpolysaccharide, preferably pentosane polysulfate or a pharmaceuticallyacceptable salt thereof, for use in:

-   -   treating or preventing a coronavirus infection;    -   reducing the severity of a coronavirus infection;    -   treating and/or preventing a disease associated with, or caused        by, a coronavirus infection;    -   treating or preventing a respiratory disease, an inflammatory        disease (including cytokine-associated toxicity), a        cardiovascular disease or a gastrointestinal disease caused by        or associated with a coronavirus infection;    -   treating or preventing cytokine-associated toxicity caused by or        associated with a coronavirus infection; and/or    -   treating or preventing one or more of fever, hypotension,        tachycardia, myalgia, headache or inappropriate cytokine release        induced by coronavirus infection.

As used herein, except where the context requires otherwise, the term“comprise” and variations of the term, such as “comprising”, “comprises”and “comprised”, are not intended to exclude further additives,components, integers or steps.

Further aspects of the present invention and further embodiments of theaspects described in the preceding paragraphs will become apparent fromthe following description, given by way of example and with reference tothe accompanying drawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 : Inhibition of SARS-CoV-2 replication by polysulfatedpolysaccharides. Data presented is inhibition by polysaccharide relativeto control.

FIG. 2 : M100 microscopy image of HCT116 cells fed FITC-NaPPS (green)then immunostained for Rab9 (red). Extensive cytoplasmic, perinuclearcolocalization of the Rab9 with NaPPS was observed in HCT116 cells(arrows).

FIG. 3 : M100 microscopy image of HCT116 cells fed FITC-NaPPS (green)then immunostained for TGN46 (red) a marker of the trans golgi network.TGN36 stained the trans golgi in classical cisternal morphology. NaPPSaccumulation was observed in close proximity to edges of the trans golgistacks. (arrows).

DETAILED DESCRIPTION OF THE EMBODIMENTS

It will be understood that the invention disclosed and defined in thisspecification extends to all alternative combinations of two or more ofthe individual features mentioned or evident from the text or drawings.All of these different combinations constitute various alternativeaspects of the invention.

Reference will now be made in detail to certain embodiments of theinvention. While the invention will be described in conjunction with theembodiments, it will be understood that the intention is not to limitthe invention to those embodiments. On the contrary, the invention isintended to cover all alternatives, modifications, and equivalents,which may be included within the scope of the present invention asdefined by the claims.

One skilled in the art will recognize many methods and materials similaror equivalent to those described herein, which could be used in thepractice of the present invention. The present invention is in no waylimited to the methods and materials described. It will be understoodthat the invention disclosed and defined in this specification extendsto all alternative combinations of two or more of the individualfeatures mentioned or evident from the text or drawings. All of thesedifferent combinations constitute various alternative aspects of theinvention.

The present invention is based on the surprising finding by theinventor, that polysulfated polysaccharides are useful in reducing theseverity coronavirus infection and can be used to treat diseases orconditions associated with, or caused by, coronavirus infection. Inparticular, the inventor has found that the polysulfated polysaccharidepentosan polysulfate (PPS) is significantly more effective at reducingreplication of SARS-CoV-2 compared to other polysulfated polysaccharidesand can therefore be used to reduce the severity of or prevent infectionby SARS-CoV-2. The methods of the present invention are therefore alsouseful for reducing the likelihood of a subject developing severedisease and/or cytokine associated toxicity arising from infection witha coronavirus.

Coronavirus

“Coronavirus” as used herein refers to members of the subfamilyCoronavirinae in the family Coronaviridae and the order Nidovirales(International Committee on Taxonomy of Viruses). This subfamilyconsists of four genera, Alphacoronavirus, Betacoronavirus,Gammacoronavirus and Deltacoronavirus, on the basis of theirphylogenetic relationships and genomic structures. Subgroup clusters arelabeled as 1a and 1b for the Alphacoronavirus and 2a, 2b, 2c, and 2d forthe Betacoronavirus. The alphacoronaviruses and betacoronaviruses infectonly mammals. The gammacoronaviruses and deltacoronaviruses infectbirds, but some of them can also infect mammals. Alphacoronaviruses andbetacoronaviruses usually cause respiratory illness in humans andgastroenteritis in animals. The three highly pathogenic viruses,SARS-CoV, MERS-CoV and SARS-CoV-2, cause severe respiratory syndrome inhumans, and the other four human coronaviruses (HCoV-NL63, HCoV-229E,HCoV-OC43 and HKU1) induce only mild upper respiratory diseases inimmunocompetent hosts, although some of them can cause severe infectionsin infants, young children and elderly individuals. Alphacoronavirusesand betacoronaviruses can pose a heavy disease burden on livestock;these viruses include porcine transmissible gastroenteritis virus,porcine enteric diarrhoea virus (PEDV) and the recently emerged swineacute diarrhoea syndrome coronavirus (SADS-CoV). On the basis of currentsequence databases, all human coronaviruses have animal origins:SARS-CoV, MERS-CoV, SARS-CoV-2, HCoV-NL63 and HCoV-229E are consideredto have originated in bats; HCoV-OC43 and HKU1 likely originated fromrodents.

The coronaviruses include antigenic groups I, II, and III. Non-limitingexamples of coronaviruses include SARS coronavirus, MERS coronavirus,transmissible gastroenteritis virus (TGEV), human respiratorycoronavirus, porcine respiratory coronavirus, canine coronavirus, felineenteric coronavirus, feline infectious peritonitis virus, rabbitcoronavirus, murine hepatitis virus, sialodacryoadenitis virus, porcinehemagglutinating encephalomyelitis virus, bovine coronavirus, avianinfectious bronchitis virus, and turkey coronavirus, as well as anyothers described herein, and including those referred to in Cui, et al.Nature Reviews Microbiology volume 17, pages 181-192 (2019), and Shereenet al. Journal of Advanced Research, Volume 24, July 2020 (publishedonline 16 Mar. 2020), Pages 91-98.

A subject or individual in need of treatment according to any aspect ofthe invention, or requiring administration of any composition describedherein, may be an individual who is displaying a symptom of acoronavirus infection or who has been diagnosed with a coronavirusinfection. Further, the subject or individual may be one who has beenclinically or biochemically determined to be infected with a coronavirus(e.g., via sequencing of blood samples or sequencing or antibody-basedapproaches for detecting coronavirus in nasal and/or nasopharangealswabs, or from a saliva-based assay).

A subject may be in a stage of coronavirus infection before endstage-organ failure has developed. A subject in need thereof may beanyone with a coronavirus infection from the onset of clinicalprogression, before end-organ failure has developed. In one embodiment,the subject has had coronavirus infection symptoms for less than orequal to 12 days, and who does not have life-threatening organdysfunction or organ failure. Preferably the subject is early in thecourse of the disease, for example, before day 14 from symptom onset, orduring the viremic and seronegative stage.

A subject may have recovered from symptoms or signs of infection butstill be shedding or carrying viral particles. A subject may have “longCOVID” and be presenting with signs or symptoms of a past coronavirusinfection.

A “subject” or “individual” can also be any animal that is susceptibleto infection by coronavirus and/or susceptible to diseases or disorderscaused by coronavirus infection. A subject of this invention can be amammal and in particular embodiments is a human, which can be an infant,a child, an adult or an elderly adult.

A “subject at risk of infection by a coronavirus” or a “subject at riskof coronavirus infection” is any subject who may be or has been exposedto a coronavirus. “Subject” or “individual” includes any human ornon-human animal. Thus, in addition to being useful for human treatment,the compounds of the present invention may also be useful for veterinarytreatment of mammals, including companion animals and farm animals, suchas, but not limited to dogs, cats, horses, cows, sheep, and pigs, or anyanimal that can be infected by coronavirus.

Subjects at risk include, but are not limited to, an immunocompromisedperson, an elderly adult (more than 65 years of age), children youngerthan 2 years of age, healthcare workers, adults or children in closecontact with a person(s) with confirmed or suspected coronavirusinfection, and people with underlying medical conditions such aspulmonary infection, heart disease or diabetes, primary or secondaryimmunodeficiency.

Treatment of Coronavirus Infection and of Diseases and ConditionsAssociated with Coronavirus Infection

Among the conditions associated with coronavirus infection, particularlyinfection with SARS-CoV-2, is an inappropriate or uncontrolledactivation of the immune system, otherwise referred to as “cytokinestorm” or “cytokine associated toxicity”.

Inappropriate or uncontrolled activation of the immune system can resultin a potentially fatal immune reaction consisting of a positive feedbackloop between cytokines and white blood cells, with highly elevatedlevels of various cytokines. Such uncontrolled immune activation, oftencalled a cytokine cascade, cytokine associated toxicity, cytokinerelease syndrome can be induced by a number of physical conditions ormedical therapies, most notably immunotherapies which specificallyexploit the immune system of the recipient to fight a disease. Cytokinestorms have been demonstrated as a result of coronavirus infection.

Aberrant cytokine release may result from graft versus host disease(GVHD), avian influenza, smallpox, pandemic influenza, adult respiratorydistress syndrome (ARDS), severe acute respiratory syndrome (SARS),sepsis, and systemic inflammatory response syndrome (SIRS). In fact, thecause of death in many of these conditions is not the pathology itself,but rather the effect of the cytokine cascade or storm that is inducedas a result of the pathology. For example, cytokine storms are thoughtto be responsible for the disproportionate deaths of many healthy youngadults during the flu pandemic of 1918. That is: the influenza wasn'tthe cause of death, but rather, the immune system's uncontrolledactivation in response to the infection.

Although different terms may be used to describe cytokine storm,cytokine cascade or cytokine release syndrome, all of these conditionshave in common the uncontrolled activation of the immune system, whichcan lead to potentially fatal consequences.

Current approaches for managing cytokine-associated toxicities involvethe use of immunosuppressive agents, including monoclonal antibodieswhich bind IL-6, corticosteroids as well as vasopressors (such asnoradrenaline, adrenaline and dopamine). A problem with this approach,however, is that in seeking to prevent or control cytokine-associatedtoxicity by immunosuppression, there is a risk of diminishing theefficacy of the immunotherapy.

Accordingly, there is a need for new approaches for treating orpreventing cytokine-associated toxicity from immunotherapy, thatfacilitates or effectuates prevention, control, down-regulation, and/ortermination of cytokine-associated toxicity, and which reduce orminimize a likelihood that undesirable side effects will occur.

The present inventor has surprisingly found that sulfatedpolysaccharides can be used to control the release of cytokines as aresult of aberrant immune system activation, whether that activationarises as a result of coronavirus infection, avian influenza, smallpox,pandemic influenza, adult respiratory distress syndrome (ARDS), severeacute respiratory syndrome (SARS), sepsis, and systemic inflammatoryresponse syndrome (SIRS).

Accordingly, in a first aspect, the present method relates to a methodof treating coronavirus infection, including

-   -   providing an individual who is suspected of having coronavirus        infection,    -   administering to the individual, an amount of a sulfated        polysaccharide or a pharmaceutically acceptable salt thereof        effective to treat the coronavirus infection

thereby treating coronavirus infection in the individual.

The present invention also contemplates the use of sulfatedpolysaccharides as a means for preventing the onset of coronavirusinfection in an individual, particularly where the individual is exposedto coronavirus.

Examples of pro-inflammatory cytokines or pro-inflammatory mediatorsinclude interleukin-1 alpha (IL-1 α) and interleukin-1-beta (IL-1β)(hereinafter collectively referred to as interleukin-1 or IL-1),interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-11 (IL-11),interleukin-12 (IL-12), interleukin-17 (IL-17), interleukin-18 (IL-18),tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ),granulocyte-macrophage colony stimulating factor (GM-CSF), andtransforming growth factor-beta (TGF-β). It will be appreciated by theskilled person that references to pro-inflammatory cytokines in mostembodiments of the present disclosure can refer any one or more ofpro-inflammatory cytokines known in the art, and including one or moreof the above-listed examples of pro-inflammatory cytokines.

In some embodiments, the decrease in quantity of pro-inflammatorycytokines within the individual assists in preventing, controlling,down-regulating, and/or stopping the occurrence of a cytokine-associatedtoxicity in the individual.

In some embodiments, the use of sulfated polysaccharides in accordancewith the methods of the present invention, affects an anti-inflammatorycytokine, anti-inflammatory mediator, or anti-inflammatory factorcondition, for instance by facilitating or effectuating increase in aquantity of the anti-inflammatory cytokine, anti-inflammatory mediator,and/or anti-inflammatory factor within the living organism. Examples ofanti-inflammatory cytokines, anti-inflammatory mediators, and/oranti-inflammatory factors include interleukin-2 (IL-2), interleukin-4(IL-4), interleukin-13 (IL-13), and interferon-alpha (IFN-α). A personof skill in the art will understand that a reference toanti-inflammatory cytokines, anti-inflammatory mediators, and/oranti-inflammatory factors in most embodiments of the present disclosurecan relate to any one or more of anti-inflammatory cytokines,anti-inflammatory mediators, and/or anti-inflammatory factors known inthe art, which includes the above-listed examples.

In some embodiments of the present disclosure, the use of sulfatedpolysaccharide facilitates or effectuates a decrease in gene expressionof one or more pro-inflammatory cytokines within the body. For example,in several embodiments, the administration of sulfated polysaccharide tothe individual at risk or suspected of having a cytokine-associatedtoxicity facilitates or effectuates decrease in IL-1 gene expression ofan immune cell (i.e. a cell that is involved in immune responses) of thebody. Examples of immune cells include lymphocytes, phagocytic cells,fibroblasts, monocytes, neutrophils, and macrophages.

In some embodiments of the present disclosure, the administration ofsulfated polysaccharide facilitates or effectuates a decrease insecretion or release of one or more pro-inflammatory cytokines by animmune cell within the body. For example, in several embodiments, thesulfated polysaccharide facilitates or effectuates a decrease in IL-1release or secretion from the immune cell.

In numerous embodiments, the decrease in gene expression of thepro-inflammatory cytokine (e.g., gene expression of IL-1) results in thedecrease of secretion of the pro-inflammatory cytokine (e.g., decreasesecretion of IL-1) by the immune cell, and hence a lower quantity ofpro-inflammatory cytokine (e.g., lower quantity of IL-1) within thebody. The lower quantity of pro-inflammatory cytokines (e.g., IL-1)within the body facilitates or effectuates or provides ananti-inflammatory effect.

In some embodiments of the present disclosure, the administration ofsulfated polysaccharide facilitates or effectuates an increase in geneexpression of one or more anti-inflammatory cytokine within the body.For example, in several embodiments, sulfated polysaccharide facilitatesor effectuates increased gene expression of IL-2 by the immune cells ofthe body. In some embodiments of sulfated polysaccharide facilitates oreffectuates an increase in secretion or release of one or moreanti-inflammatory cytokine by immune cells within the body. For example,in several embodiments, sulfated polysaccharide facilitates oreffectuates increased secretion of IL-2 by the immune cells of the body.

In yet further embodiment, the increase in the gene expression of one ormore anti-inflammatory cytokines (e.g., IL-2) results in the increasedsecretion of the one or more anti-inflammatory cytokines by the immunecells of the body, and therefore a higher quantity of anti-inflammatorycytokines within the body. The higher quantity of anti-inflammatorycytokines within the body facilitates or effectuates or provides ananti-inflammatory effect.

A reduction in coronavirus infection may be determined using any methodknown in the art or described herein, including measuring viral load ina sample from the subject after treatment and comparing it to viral loadin a sample from the same subject before treatment. The sample may beany biological sample obtained from the subject, and may include blood,saliva, urine, faeces, nasal wash, sputum, and mucous secretions. Thesample may be taken from the respiratory tract, preferably the upperrespiratory tract, for example the nose or pharynx (i.e. throat).

The term ‘respiratory disease’ or ‘respiratory condition’ refers to anyone of several ailments that involve inflammation and affect a componentof the respiratory system including the upper (including the nasalcavity, pharynx and larynx) and lower respiratory tract (includingtrachea, bronchi and lungs). The inflammation in the upper and lowerrespiratory tract may be associated with or caused by viral infection.

A symptom of respiratory disease may include cough, excess sputumproduction, a sense of breathlessness or chest tightness with audiblewheeze.

The existence of, improvement in, treatment of or prevention of arespiratory disease may be determined by any clinically or biochemicallyrelevant method of the subject or a biopsy therefrom. For example, aparameter measured may be the presence or degree of lung function, signsand symptoms of obstruction; exercise tolerance; night time awakenings;days lost to school or work; bronchodilator usage; Inhaledcorticosteroid (ICS) dose; oral glucocorticoid (GC) usage; need forother medications; need for medical treatment; hospital admission.

As used herein, the term respiratory infection means an infection by acoronavirus, preferably by SARS-CoV-2, anywhere in the respiratorytract.

An individual may be identified as having a respiratory tract infectionby viral testing and may exhibit symptoms of itchy watery eyes, nasaldischarge, nasal congestion, sneezing, sore throat, cough, headache,fever, malaise, fatigue and weakness. In one aspect, a subject having arespiratory infection may not have any other respiratory condition.Detection of the presence or amount of virus may be by PCR/sequencing ofRNA isolated from clinical samples (nasal wash, sputum, BAL) orserology.

The terms “treatment” or “treating” of a subject includes theapplication or administration of polysulfated polysaccharide asdescribed herein, with the purpose of delaying, slowing, stabilizing,curing, healing, alleviating, relieving, altering, remedying, lessworsening, ameliorating, improving, or affecting the disease orcondition, the symptom of the disease or condition, or the risk of (orsusceptibility to) the disease or condition.

The term “treating” refers to any indication of success in the treatmentor amelioration of an injury, pathology or condition, including anyobjective or subjective parameter such as abatement; remission;lessening of the rate of worsening; lessening severity of the disease;stabilization, diminishing of symptoms or making the injury, pathologyor condition more tolerable to the subject; slowing in the rate ofdegeneration or decline; making the final point of degeneration lessdebilitating; or improving a subject's physical or mental well-being.

It will be appreciated that coronavirus infection may not necessarilylead to severe disease, such as cytokine storm. The present invention,therefore contemplates the use of sulfated polysaccharides for thetreatment of any symptom of coronavirus infection, regardless of howmild or severe. Thus, the present invention includes methods of treatingindividuals who have relatively mild symptoms of infection, such asheadache, fever, cough and fatigue. Such individuals will generally notrequire hospitalisation (and can be treated at home). Other individualsmay have sufficiently severe symptoms that may require hospitalisation,although it will be appreciated that such individuals may notnecessarily develop cytokine storm.

Further still, it is to be recognised that not all instances ofcoronavirus infection are symptomatic, including infection withSARS-CoV-2. However, given the findings of the present inventor, it willbe appreciated that the methods of the invention find application in thetreating of an infection (including to reduce viral load in theindividual), even when the individual is asymptomatic. Such individualsmay easily be identified through the use of routine screening of faecal,nasal and/or nasopharangeal swabs. Moreover, it will be appreciated thatthis approach reduces the likelihood of an individual spreading theirinfection to others, and consequently the methods of the invention canbe extended to a method for reducing the likelihood of transmission of acoronavirus infection to another individual.

Given the breadth of symptoms caused by coronaviruses, (and range ofseverity thereof) including by SARS-CoV-2, it will be appreciated that apositive response to therapy according to the methods described herein,may include any amelioration or improvement of symptoms experienced bythe subject.

For example, a positive response to therapy may be a reduction ingeneral levels of fatigue, muscle pain, headache and/or lethargy in thesubject. A positive response may also include a reduction in fever, anda return to afebrile state in the subject.

A positive response to therapy may also be prevention or attenuation ofworsening of respiratory symptoms following a respiratory virusinfection. This could be assessed by comparison of the mean change indisease score from baseline to end of study period, for example, basedon a questionnaire, and could also assess lower respiratory symptomscore (LRSS—symptoms of chest tightness, wheeze, shortness or breath andcough) daily following infection/onset of cold symptoms. Change frombaseline lung function (peak expiratory flow PEF) could also be assessedand a positive response to therapy could be a significant attenuation inreduced PEF. For example, a placebo treated group would show asignificant reduction in morning PEF of 15% at the peak of exacerbationwhilst the treatment group would show a non-significant reduction in PEFless than 15% change from baseline.

A positive response to therapy may also be a reduction in the presenceof ground-glass type opacities in the lung periphery or near the pleura(for example, as determined using chest CT imaging techniques).

A positive response to therapy may also include an increase or return tonormal levels of blood oxygenation levels.

A positive response to therapy may also include an improvement incardiovascular disorders such as alterations in blood pressure andincreased presence of clotting factors.

The methods of the present invention can further be applied once anindividual has recovered from an initial coronavirus infection. Suchmethods may find utility in the treatment of “long covid” symptoms, orin individuals who have long periods of viral particle excretion. Themethods of the invention can also be utilised to prevent or reduce thelikelihood of reinfection with coronavirus, including re-infection withSARS-CoV-2 (and variants thereof).

Sulfated Polysaccharides

As used herein, the term sulfated polysaccharide includes sulfatedpolysaccharides, sulfated oligosaccharides and glycosaminoglcans,including glycosaminoglycans linked to a core protein, such as heparinsulfate proteoglycans.

Non-limiting examples of sulfated polysaccharides include: pentosanpolysulfate (PPS), chondroitin sulfate A, chondroitin sulfate B,chondroitin sulfate C, keratan sulfate, heparin, heparan sulfate,dextran polysulfate, fucoidan, lentinan sulfate, mannan sulfate,galactan sulfate, xylomannan sulfate, rhamnan sulfate, curdlan sulfateand sulfated fucan.

The invention also contemplates the use of various pharmaceuticallyacceptable salts of any one of the above mentioned sulfatedpolysaccharides, including but not limited to the sodium, calcium,potassium and magnesium salts.

Accordingly, in a further aspect, the present method relates to a methodof treating cytokine-associated toxicity, including

-   -   providing an individual who is suspected of having        cytokine-associated toxicity,    -   administering to the individual, an amount of a polysulfated        polysaccharide or a pharmaceutically acceptable salt thereof        effective to treat the cytokine-associated toxicity

wherein the polysulfated polysaccharide is selected from the groupconsisting of pentosan polysulfate, chondroitin sulfate A, chondroitinsulfate B, chondroitin sulfate C, keratan sulfate, heparin, heparansulfate, dextran polysulfate, fucoidan, lentinan sulfate, mannansulfate, galactan sulfate, xylomannan sulfate, rhamnan sulfate, curdlansulfate, or sulfated fucan.

The present invention also contemplates the use of molecular weightvariations of any one of the sulfated polysaccharides described herein,including molecular weights ranging from 100 to 10,000,000 mass units,preferably 1,000 to 100,000 mass units, more preferably 1,800 to 9,000mass units.

The skilled person will also appreciate that the degree of sulfation ofthe sulfated polyaccharides described herein may also vary. Varyingdegrees of sulfation occur in both naturally occurring and syntheticsulfated polysaccharides. The degree of sulfation of the sulfatedpolysaccharide may be preferably about 0.5, 0.6, 0.7, 0.8, 0.9, 1.0,1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, or more than 2.0. In apreferred embodiment the invention relates to a sulfated polysaccharidefor use as described herein, wherein the degree of sulfation of thepolysaccharide is high, for example, 1.9.

Pentosan Polysulfate

In a particularly preferred embodiment of the present invention, thesulfated polysaccharide is pentosan polysulfate (PPS; also known as[(2R,3R,4S,5R)-2-hydroxy-5-[(2S,3R,4S,5R)-5-hydroxy-3,4-disulfooxyoxan-2-yl]oxy-3-sulfooxyoxan-4-yl]hydrogen sulfate) is a semi-synthetically derived heparin-likemacromolecule carbohydrate derivative, which chemically and structurallyresembles glycosaminoglycans (GAGs). There are 40 synonyms listed forpentosan polysulfate on PubChem including BAY-946, HOE-946, pentosansulfuric polyester, polypentose sulfate, polysulfated xylan, PZ-68,SP-54, xylan SP54 and xylan sulfate. PPS is disclosed in U.S. Pat. No.2,689,848 and this compound has been known since the early 1960s to be asynthetic heparinoid and an anti-thrombotic agent. PPS was originallydeveloped as a heparin-like agent which interferes with the binding offactor Xa to thrombin via an AT-III independent mechanism. While havingsimilar structural properties to heparin, PPS is more heavily sulfatedand consequently has a greater overall negative charge. Further, PPS hasonly about 1/15 the anticoagulant properties of heparin.

PPS is most commonly used as an oral formulation to treat interstitialcystitis in humans and as an injectable drug to treat osteoarthritis incompanion animals (Fuller, Ghosh et al., “Plasma and synovial fluidconcentrations of calcium pentosan polysulfate achieved in the horsefollowing intramuscular injection,” Equine Veterinary Journal (2002)).The compound PPS may also be used as an anticoagulant, preventing theformation of blood clots, although it has 1/15 the anti-coagulantproperties if heparin. PPS has also been used for treatment ofhematomes, hemorrhoids, frostbites, burns, and multiparameter illnessessuch as thrombosis and atherosclerosis.

In the context of interstitial cystitis, PPS is believed to provide aprotective coating to the damaged bladder wall due to is similarstructure with the natural glycosaminoglycan coating of the inner liningof the bladder. Thus, it is thought that PPS may replace or repair thelining of the bladder in interstitial cystitis, reducing itspermeability.

The mechanism of PPS action in osteoarthritis is multifactorial, withboth stimulation of cartilage matrix synthesis and prevention ofcartilage breakdown. There are also systemic effects on blood lipids andfibrinolysis that may help clear the subchondral circulation.

PPS is obtained by sulfate esterification of beechwood (Fagus sylvatica)hemicellulose and consists of a mixture of polymers with molecularweight ranging from 1,800 to 9,000 mass units (mean 4,700 units). PPS isproduced from a chemical solution of polysaccharides (e.g. Xylan)extracted from the bark of the beech tree or other plant sources whichis then treated with sulfating agents such as chlorosulfonic acid orsulfuryl chloride and an acid. After sulfation, PPS is usually treatedwith sodium hydroxide to yield the sodium salt.

Various methods have been described for the preparation of PPS includingWO/2008/107906, WO/2009/047699 and WO/2012/114349, the entire contentsof which are herein incorporated by reference.

In some embodiments, the polysulfated polysaccharide for use inaccordance with the methods of the present invention, is the sodiumpentosan polysulfate manufactured to the specifications lodged with theUS FDA and European Community EMEA by Bene-PharmaChem GmbH & Co KG,Geretsried, Germany.

In various embodiments, the molecular weight ranges as 100 to 10,000,000mass units, preferably 1,000 to 100,000 mass units, more preferably1,800 to 9,000 mass units.

The basic structure of PPS consists of pentoses, i. e. (1->4) linkedbeta-D-xylopyranose units containing glucuronic acid groups atstatistically every 10th unit.

Below is the structural formula of pentosan polysulfate (PPS) isolatedfrom beechwood hemicellulose. This formula shows that the linear xylan(pentosan) backbone of pentosan polysulfate contains on average one4-0-methyl glucuronate side chain linked to the 2-position on everytenth xylose (pentose) ring.

The sodium derivative is when R=SO3Na. The calcium derivative of PPS(CaPPS) is when R=SO3Ca⁺¹ or SO3Ca⁺². The magnesium derivate of PPS(MgPPS) is when R=SO3Mg⁺¹ or SO3Mg⁺².

Pentosan polysulfate (PPS) is available as an alkali metal salt oralkaline earth metal salt, for example, comprising calcium or sodiumsalt, or transition metals such as copper and zinc and noble metals suchas platinum. Accordingly, the particular complexing ions may be selectedfrom the group consisting of the alkali metals, e.g. Na+ and alkalineearth metals, e.g. Ca2+, Zn2+, Mg2+, Ba2+, as well as Ag+, Pb2+, Cu2+,Au2+, Pd2+, Pd4+, Pd4+, Pd2+, trivalent metal ions, and quaternaryammonium compound complexes. Examples of the latter compound arepyridinium chloride, tetraalkyl ammonium chloride, chorine chloride,cetylpyridinium chloride, N-cetyl-N,N,N-trialkylammonium chloride ortheir derivatives. Preparation of the polysulfate polysaccharide-metalcomplexes is described in detail in U.S. Pat. No. 5,668,116, the entiredisclosure of which is incorporated herein by reference.

Accordingly, in a yet further embodiment, the pharmaceuticallyacceptable salt of pentosan polysulfate used in the method of thepresent invention, is the sodium salt of pentosan polysulfate (NaPPS),the magnesium salt of pentosan polysulfate (MgPPS), and/or the calciumsalt of pentosan polysulfate (CaPPS). Preferably, the sodium salt isused in the methods of the present invention.

In yet further embodiments, the present invention includes the use ofpentosan polysulfate having varying degrees of sulfation. For example,the degree of sulfation may be from 0.2 to 2 sulfates per sugar moiety.In a preferred embodiment, the degree of sulfation may be 1.9 per sugarmoiety.

The present invention also encompasses biologically active molecularfragments of PPS or analogues or derivatives of PPS.

A significant advantage of the present invention over the currentapproaches for treating cytokine-associated toxicity, is the well-knownsafety profile of PPS. Even when administered at high doses for extendedperiods, PPS has been reported to produce only limited side effects(Nickel et al., 2005). A further advantage is that PPS is bioavailablewhen administered orally, intravenously or subcutaneously (which is incontrast to other GAGs).

Cytokine Associated Toxicity

As used herein, cytokine-associated toxicity refers to a potentiallylife-threatening adverse cytokine response to aberrant immune systemactivation, for example caused by illness but also including animmunomodulating therapy.

Cytokine-associated toxicity is also described in the art using the termcytokine release syndrome (CRS). When sufficiently severe, this syndromecan be referred to as hypercytokinemia or ‘cytokine storm’. As usedherein, CRS defines a systemic inflammatory response in a patient interalia characterized by hypotension, pyrexia and/or rigors, andpotentially resulting in death. CRS is believed to be caused by anuncontrolled positive feedback loop between cytokines and immune cells,resulting in highly elevated levels of various cytokines. CRS alsoinvolves the systemic expression of immune system mediators and includesincreased levels of pro-inflammatory cytokines and anti-inflammatorycytokines.

During a cytokine storm, inflammatory mediators, for examplepro-inflammatory cytokines such as Interleukin-1 (IL1), Interleukin-6(IL6), tumor necrosis factor-alpha (TNF-alpha), oxygen free radicals,and coagulation factors are released by the immune cells of the body.Cytokine storms have the potential to cause significant damage to bodytissues and organs. For example, occurrence of cytokine storms in thelungs can cause an accumulation of fluids and immune cells, for examplemacrophages, in the lungs, and eventually block off the body's airwaysthereby resulting in respiratory distress and even death.

As described above, the present invention relates to a method oftreating or preventing cytokine-associate toxicity (or adverse cytokineresponse). In certain embodiments, the cytokine-associated toxicity issufficiently severe to be classified as a “cytokine storm” orhypercytokinemia. Accordingly, in a further embodiment, the presentinvention relates to a method of treating hypercytokinemia in anindividual, including

-   -   providing an individual at risk of or suspected of having        hypercytokinemia,    -   administering to the individual, an amount of sulfated        polysaccharide, or a pharmaceutically acceptable salt thereof,        effective to treat hypercytokinemia

thereby treating hypercytokinemia in the individual.

The hypercytonokinemia may be induced by graft versus host disease(GVHD), acute respiratory distress syndrome (ARDS), sepsis, systemicinflammatory response syndrome (SIRS), severe viral infection, shock,pneumonia severe acute respiratory syndrome (SARS), or immunotherapy.

Accordingly, the method also provides for a method of treatinghypercytokinemia induced by graft versus host disease (GVHD), acuterespiratory distress syndrome (ARDS), sepsis, systemic inflammatoryresponse syndrome (SIRS), severe viral infection, shock, pneumoniasevere acute respiratory syndrome (SARS), or immunotherapy, in anindividual, including

-   -   providing an individual at risk of or suspected of having        hypercytokinemia induced by graft versus host disease (GVHD),        acute respiratory distress syndrome (ARDS), sepsis, systemic        inflammatory response syndrome (SIRS), severe viral infection,        shock, pneumonia severe acute respiratory syndrome (SARS), or        immunotherapy.        -   administering to the individual, an amount of sulfated            polysaccharide, or a pharmaceutically acceptable salt            thereof, effective to treat hypercytokinemia

thereby treating hypercytokinemia in the individual.

Administration of Sulfated Polysaccharides

According to various embodiments of the present invention, the sulfatedpolysaccharide formulations are preferably administered to humans whoare at risk or suspected of having coronavirus infection (includingcytokine-associated toxicity associated therewith). However, it will beunderstood that, although this specification refers specifically toapplications in humans, the invention is also useful for veterinarypurposes. Thus in all aspects the invention is useful for domesticanimals such as cattle, sheep, horses and poultry; for companion animalssuch as cats and dogs; and for zoo animals. Therefore, the general term“subject” or “subject to be/being treated” is understood to include allanimals (such as humans, apes, dogs, cats, horses, and cows) that havean enhanced immune response, whether caused by immunotherapy or as theresult of another condition.

The methods described herein may involve the use of topical and systemicformulations for oral, intravenous, intramuscular, intra-articular, orsubcutaneous administration of the sulfated polysaccharides. Variousother embodiments may be formulated to be administered by way of atransdermal patch, a cream, intravenous solution, eye drops, spray,liposomes or any other method of application and ingestion (includingthrough the use of a gastric tube)

In further embodiments, the sulphated polysaccharides may be adapted foradministration by inhalation, for delivery to the upper or lowerrespiratory tract, Including the nasal and nasopharangeal tracts.

According to some embodiments, liquid (e.g., aqueous) sulfatedpolysaccharide formulations may be administered via injection. In someembodiments, liquid formulations may be administered orally. In someembodiments, liquid formulations may not be terminally sterilized.

The formulations described herein can be further processed by knownmethods to produce a pharmaceutically acceptable composition. In certaininstances, this may entail using a pharmaceutically acceptable carrierwith any of the formulations described herein, whether that carrier isin a liquid or solid format. For example, the formulation can be furtherprocessed so as to be administered in any suitable liquid or powderform, such as by pill, capsule, liquid, liposome, lyophilizedcomposition, hard or soft chewable tablet. The formulation may beadministered, e.g., to a mammal, in one or more dosage forms. Dosageforms of the formulation may be administered in an amount effective totreat one or more diseases.

The term “administered” means administration of a therapeuticallyeffective dose of the aforementioned composition including therespective cells to an individual. By “therapeutically effective amount”is meant a dose that produces the effects for which it is administered.The exact dose will depend on the purpose of the treatment, and will beascertainable by one skilled in the art using known techniques. As isknown in the art and described above, adjustments for systemic versuslocalized delivery, age, body weight, general health, sex, diet, time ofadministration, drug interaction and the severity of the condition maybe necessary, and will be ascertainable with routine experimentation bythose skilled in the art.

Formulations

Methods of preparing various formulations of sulfated polysaccharideswill be within the purview of the skilled person. In particular, theskilled person will be familiar with preparing oral or injectable dosageforms, depending on the preferred mode of administration of sulfatedpolysaccharides.

In certain preferred embodiments, the methods of the invention involveuse or administration of an oral formulation. Oral formulations may becapsules, for example hard gelatine capsules and may contain excipientssuch as microcrystalline cellulose and lubricants such as magnesiumstearate. The sulfated polysaccharide may be present in an amount of 10mg to 1 g, or preferably about 100 mg.

Various formulations in accordance with the present invention maycomprise one or more of the foregoing components in any suitableconcentration or amount. For example, the sulfated polysaccharide may bepresent in a concentration of about 25 mg/mL to about 750 mg/mL orpreferably about 25 to about 500 mg/mL, or more preferably about 250mg/mL. In another example, the sulfated polysaccharide may be present ina total amount of about 10 mg to about 5 g. Buffers, for example,including sodium citrate, citric acid, or other buffers, may be presentin concentrations such as about 1 to about 100 mM. For example, in someembodiments, a buffer such as sodium citrate may have concentrations inthe formulation of about 50 mM (14.7 mg/mL), or a buffer such as citricacid may comprise about 55 mM (about 10.5 mg/mL). EDTA may be present inconcentrations such as about 0.01% to about 0.5% w/v, 0.1 mM to about 1mM, about 0.25 mg/mL, or more preferably about 0.25% w/v.

Chelators may be present in concentrations such as about 0.1 to about 1mM. Preservatives may be present in concentrations such as about 0.1% toabout 1%. Antioxidants may be present in concentrations such as about0.1 to 10 mM. Antioxidants may also be present in concentrations ofabout 0.02% w/v to about 5% w/v. Excipients (e.g., pharmaceuticalexcipients) may be present in any suitable concentration, e.g.,concentrations of about 1 to about 90%.

In other embodiments of the invention, various formulations may compriseone or more of these components in any suitable concentration or amount.For example, the sulfated polysaccharide, for example, PPS, may bepresent in a concentration of about 25 mg/mL to about 500 mg/mL, or morepreferably about 250 mg/mL. Buffers may be present in concentrationssuch as of about 0.005% to about 5% w/v. Sodium bisulfite may be presentin concentrations such as about 0.01% to about 1% w/v, about 0.02% toabout 1% w/v, 10 mg/mL, or more preferably about 1% w/v. (When added toformulation of the present invention, sodium metabisulfite can convertto sulfur dioxide and sodium bisulfite. In embodiments, between about25% and almost all of the metabisulfite may, upon addition toformulations of the present invention, convert to sulfur dioxide andsodium bisulfite.)

EDTA may be present in concentrations such as about 0.01% to about 0.5%w/v, 0.1 mM to about 1 mM, about 0.25 mg/mL, or more preferably about0.25% w/v. Sodium citrate may be present in concentrations such as about0.1 to about 4% w/v, or more preferably about 1.47% w/v. Citric acid maybe present in concentrations such as about 0.5% to about 2% w/v, or morepreferably about 1.05% w/v. Antimicrobial agents such as methyl parabenmay be present in concentrations such as about 0.05% to about 0.2% w/v,or about 1 mg/mL, or more preferably about 0.1% w/v.

The formulations of the present invention may be in a liquid, solid, orlyophilized form and may be formulated as an aqueous solution. Theformulation may be in a solution having any suitable pH, such as a pH ofabout 4 to about 8. In some embodiments, the formulation may have a pHof about 7 to about 8. For example, the formulation may be in a solutionhaving any suitable pH, such as a pH of about 4 to about 8. It should beappreciated by those of ordinary skill in the art that the formulationsof the present invention may be lyophilized to create a lyophilizeddosage form, using techniques apparent to one of ordinary skill in theart in light of this specification. In addition, lyophilized dosageforms may be formulated to comprise, after reconstitution, a dosage formof any of the formulations described herein.

An exemplary formulation may comprise one or more of the following: PPSin a concentration of about 25 to about 500 mg/mL; metabisulfite orbisulfite (e.g., sodium bisulfite) in a concentration of about 0.05% w/vto 5% w/v; one or more chelators in a concentration of about 0.01% w/vto about 0.5% w/v; one or more buffers in a concentration of about0.005% w/v to about 5% w/v; one or more antioxidants in a concentrationof about 0.02% w/v to about 1% w/v; one or more antimicrobial agents ina concentration of about 0.05% w/v to about 0.2% w/v hyaluronic acid;and glucosamine.

In some embodiments, sodium bisulfite may be present in concentrationssuch as about 10 mg/mL. EDTA may be present in concentrations such asabout 0.25 mg/mL. Sodium citrate may be present in concentrations suchas about 14.7 mg/mL. Citric acid may be present in concentrations suchas about 10.5 mg/mL. Methyl paraben may be present in concentrationssuch as about 1 mg/mL.

In one example, the dosage form may comprise pentosan polysulfate (PPS)at a concentration of about 250 mg/mL; sodium bisulfite in aconcentration of up to about 20 mg/mL; and EDTA at a concentration ofabout 0.25 mg/mL. The formulation may be stable in a pH range of about 6to about 7.

An exemplary formulation may comprise PPS in a concentration of about250 mg/mL; sodium bisulfite in a concentration of up to about 10 mg/mL;EDTA in a concentration of about 0.25 mg/mL; and methyl paraben in aconcentration of about 1 mg/mL. The formulation may be stable in a pHrange of about 5.8 to about 6.2.

Another exemplary formulation may comprise PPS in a concentration ofabout 250 mg/mL; sodium bisulfite in a concentration of up to about 10mg/mL; EDTA in a concentration of about 0.25 mg/mL; and methyl parabenin a concentration of about 1 mg/mL. The formulation may be stable in apH range of about 7.8 to about 8.2. In some embodiments, the pH of theformulation may be adjusted with 1% w/v sodium hydroxide.

In preferred embodiments, the PPS may be formulated in any dosage form,such as a liquid, e.g. for oral administration, or an injectable dosage,most preferably, for oral administration.

Oral dosage forms of PPS may comprise PPS in an amount of from 25 mg toabout 250 mg; preferably about 100 mg to about 200 mg.

Oral dosage forms may be immediate release capsules or delayed releasecapsules.

Further examples of PPS formulations are described in WO/2007/123800,the entire contents of which are herein incorporated by reference.

Dosing

The skilled person will be able to readily determine the appropriatedose of sulfated polysacchairde required for prevention or treatment ofcytokine-associated toxicity. It will be appreciated that the dose ofsulfated polysaccharide required, will depend on the severity of thetoxicity (for example, if the toxicity is considered mild cytokinerelease syndrome or more severe hypercytokinemia) and thus, the skilledperson will determine the appropriate dose on a case by case basis.Further, the degree of toxicity will also be influenced by factors suchas the severity of the disease causing the cytokine associated toxicityor the severity of the disease being treated with immunotherapy (and thedose of immunotherapy this being administered). In yet a furtherconsideration, the dose of sulfated polysaccharide may be adjusteddepending on whether the sulfated polysaccharide is intended forprophylactic (i.e., prevention) treatment of cytokine-associatedtoxicity or is intended following evidence of the individual sufferingfrom immunotherapy induced cytokine-associated toxicity.

The sulfated polysaccharide formulations used in accordance with themethods of the present invention may be formulated for administration toa mammal, e.g., for oral or injectable administration, in any of thedose ranges described below. The injection may be intravenous,intramuscular or subcutaneous.

A dose of the sulfated polysaccaride formulations for use in the methodsof the present invention, may comprise sulfated polysaccharide in anamount of about 0.001 to 100 mg/kg/day.

In a preferred embodiment, when the sulfated polysaccharide is PPS, theamount provided in an injectable dose is 10 mg to about 5 g or about 1mg/kg to about 5 mg/kg, for example. In some embodiments, a dose ofabout 3 mg/kg may be administered via injection. In some embodiments,the amount of the dosage form comprises an amount sufficient to injectabout 1 mg/kg to about 5 mg/kg of PPS at each injection.

In some embodiments, a dose of the PPS formulations described herein,e.g., a dose for oral administration, may comprise PPS in an amount ofabout 4 mg/kg to about 20 mg/kg. In some embodiments, a dose of about 10mg/kg may be administered orally. In some embodiments, the amount of theliquid formulation comprises an amount sufficient to deliver an oraldose of about 1 mg/kg to about 50 mg/kg of PPS at each administration.

It should be appreciated that smaller doses may be appropriate forhumans and small mammals, while larger doses may be appropriate forlarger animals. A dosage amount may be based on the mass of the targetsubject. For example, a dosage may comprise about 3 mg per kg of bodymass of the target subject, such as a human or a horse.

In certain embodiments, PPS is administered by continuous venousinfusion at a dose of 2 mg/kg, 3 mg/kg, 4 mg/kg, 5 mg/kg, 6 mg/kg, 7mg/kg, 8 mg/kg, 9 mg/kg, 10 mg/kg, 12 mg/kg, 15 mg/kg or 20 mg/kg for aperiod of 1-3 weeks.

In yet further embodiments, PPS is administered by subcutaneousinjection at a dose of 2 mg/kg, 3 mg/kg, 4 mg/kg, 5 mg/kg, 6 mg/kg, 7mg/kg, 8 mg/kg, 9 mg/kg, or 10 mg/kg. when administered subcutaneously,PPS is preferably administered once a day, every second day, three timesa week, or once a week.

It will be appreciated by those of ordinary skill in the art that thedosage for a particular formulation depends in part on the salt of PPSin the formulation. For example, formulations comprising sodium PPS mayhave a different dosage than formulations comprising calcium PPS. Dosagecalculations can be determined by those of skilled in the art byevaluating body weight, surface area, and species differences.

According to various embodiments of the present invention, doses may beadministered in a variety of frequencies. The frequency of dosing willvary depending on the severity of the coronavirus infection, the diseaseor condition associated with coronavirus infection including associatedcytokine-associated toxicity. For example, if it is intended for thesulfated polysaccharide to act as a prophylactic to prevent onset ofcytokine-associated toxicity, or other disease or condition or symptomassociated with coronavirus infection, it may be preferable toadminister the sulfated polysaccharide throughout the duration ofcoronavirus infection and until such time as the patient no longer hasactive infection. Alternatively, if the sulfated polysaccharide is beingused in response to the onset of cytokine-associated toxicity, then thetreatment course may be over only a short period of time and until thesymptoms of cytokine-associated toxicity are reduced.

Oral doses of the formulations described herein may be administereddaily, about once every two or three days, about twice weekly, orweekly. Injectable doses, such as intramuscular, intraarticular,subcutaneous or intravenous dosages, may be administered about daily,about once every two or three days, about twice weekly, about weekly,about bi-weekly, about monthly, or in other administration frequencies.Such doses may be administered for time periods such as about four weeksto about five weeks, about two months, about six months, or other termof treatment.

Doses described herein may also be administered in pulse therapy, e.g.,where doses are administered periodically (e.g., about every three days)for a period of time such as 1-3 months, then not administered for aperiod of time such as 1-3 months, and then administered againperiodically (e.g., about daily or at some other appropriate interval)for a time period such as 1-3 months. Other dosage regimens are apparentto one of ordinary skill in the art in light of this specification.

It will be appreciated by those of ordinary skill in the art that asingle dose of the formulations described herein, such as a single dailydose, may be administered in parts and/or at different times throughouta single day. For instance, a daily dose may be divided so that half isadministered twice per day, e.g., half in the morning and half at nightor administered three times in a single day.

Combination Treatment for Cytokine-Associated Toxicity

The present invention also contemplates the co-administration ofsulfated polysaccharides with other agents for preventing or treatingthe onset of cytokine-associated toxicity. For example, in oneembodiment, corticosteroids such as prednisolone, methylprednisolone ordexamethasone may be used in conjunction with sulfated polysaccharidesfor preventing or treating cytokine-associated toxicity.

In yet a further embodiment, an anti-IL-6 antibody may be used inconjunction with a sulfated polysaccharide for preventing or treatingcytokine-associated toxicity. For example, the IL-6 antibody may betocilizumab.

Treatments which specifically target TNF-α may also be used inconjunction with sulfated polysaccharide for preventing or treatingcytokine-associated toxicity. Examples of suitable TNF-α inhibitors areetanercept and infliximab. Angiotensin-II receptor blockers (ARBs) andangiotensin converting enzyme (ACE) inhibitors may also be suitable fordown regulating TNFα in the context of cytokine-associated toxicityincluding hypercytokinemia. Examples of suitable ARBs and ACE inhibitorsinclude losartan, telmisartan, irbesartan, olmesartan, valsartan,perindopril, trandolapril, captopril, enalapril, lisinopril, andramipril.

In yet further embodiments, the present invention also contemplates theprevention or treatment of cytokine-associated toxicity using acombination of sulfated polysaccharide and OX40-Ig (a fusion protein forpreventing binding of the ligand OX40 to recently activated T cells).

EXAMPLES Example 1: Polysulphated Polysaccharides Inhibit Replication ofCoronavirus

Materials

-   -   cell culture medium: DMEM F12+10% FCS+penstrep.    -   infection culture media: DMEM+TPCK trypsin+penstrep. (serum        free);    -   Calu-3 cells (human lung cancer cell line)

Polysulfated polysaccharides: Name Av MW (Da) Manufacturer Cat. No.Fondaparinux (pentasaccharide) S-Aldrich SML1240 Heparan sulfate >25,000S-Aldrich H7640 Pentosan polysulfate Bene Dextran sulfate 5,000S-Aldrich 31404 Pentosan polysulfate Manufacturer 2 Chondroitin sulfateA S-Aldrich C9819

Experiments were conducted as follows:

-   -   Calu3 cells were treated pre- or post-infection with the        polysulfated polysaccharides at 10 concentrations (or vehicle).    -   Cells were mock-infected or infected with SARS-CoV-2.    -   Viral loads were analysed at 1 time point by TCID50 assay,        measuring cytopathic effect induced following serial passage of        supernatant on target Vero cells.

Experiments were conducted in 96-well plates, consisting of 2 biologicalreplicates, with a replicate consisting of 1× uninfected and 2× infectedplates (pre+post), each as 60 wells/test compound/cell type (as 10compound dilutions; sextuplicate technical replicates)+6 wells/control(pos+neg; single dilution). Compound were tested in this format on thesame plate as a pre- or post-infection treatment.

Examplary Protocol

On Day 0, Calu cells were seeded in flat bottom 96 well plates in cellculture medium.

On Day 1: cells were infected with SARS-CoV-2. Briefly, 0.1 MOISARS-CoV-2 was diluted in infection culture medium, applied to cells andthen allowed to adsorb for 30 min. at 37° C., 5% CO₂. Dilutedpolysulfated polysaccharides or negative control (vehicle) were thenapplied to the infected cells. Polysulfated polysaccharides were addedat a final concentration of between about 0.03 μM to about 55 μM. Cellswere incubated in the presence of the polysulfated polysaccharides at37° C., 5% CO₂ for 2 days.

On Day 4, samples of Calu culture media were obtained for the purposesof determining TCID50 (Median Tissue Culture Infectious Dose). Briefly,Calu culture medium was diluted in serum free DMEM in round bottomplates and then plated onto confluent layers of Cero cells (6 replicatesper dilution). Cells were then incubated at 37° C., 5% CO₂ for 3 days.

On Day 7, the cytopathic effect (CPE) was calculated in order todetermine TCID50/ml.

Results

Each concentration of drug treatment was scored for cytopathic effectand the results analysed by Spearman-Karber matrix.

As shown in FIG. 1 , virus replication in Calu3 cells was inhibited muchmore strongly with PPS compared with other polysulfated polysaccharidestested. This was measured by using the supernatant from the treatedCalu3 cells in Vero cells, which undergo prominent cytopathic effect(CPE), which was then scored. Wells were scored 4 days after receivingsupernatant as either positive (CPE) or negative (no virus). TissueCulture Infectious Dose 50% (TCID50/mL) was calculated using theSpearman and Kärber test. Pentosan polysulfate (PPS) demonstrated analmost four orders of magnitude reduction in virus infectivity in theCalu3 SARS-CoV-2 in vitro model.

These results demonstrate that PPS inhibits SARS-CoV-2 viral replicationand reduces viral infectivity and therefore suggests that PPS would be auseful therapeutic for the treatment of infection with SARS-CoV-2.

Example 2: PPS Inhibits Intracellular SARS-CoV-2 Assembly in Golgi andGolgi-Associated Compartments

The SARS-COV-2 virus is known to enter cells via endosomes and thenexploit the autophagy pathway of the host cell. There is accumulatingevidence that endocytosed virus can interfere with the endogenousfunction of the autophagy-lysosome pathway and then replicate inautophagosome-like structures.

Autophagy has both canonical and non-canonical pathways. The latterutilizes autophagosomes derived from the trans-Golgi and late endosomesassociated with small GTPase Ras-related protein Rab9.

In this study fluorescently labelled NaPPS was added to a culture ofHCT116 colorectal carcinoma cells in vitro. Immunohistochemical stainingwas then used to compare the subcellular distribution of exogenous NaPPSand endogenous Rab9 endosomes.

Methods

Fluorescent tags were covalently bound to NaPPS after conversion to theethyl-amino derivative followed by coupling with isothiocyanate ester offluorescein using standard methods.

HCT116 cells were cultured on glass coverslips in DMEM with 20% fetalbovine serum and antibiotics (pen/strep) at 37° C., 5% CO₂ and 5%humidity. Cultures at 20-40% confluence were supplemented with 50 μg/mlFITC-NaPPS for 48h. Cells were then fixed with 4% paraformaldehyde inPBS then washed and incubated for 3h with a mouse antibody specific toRab9 or TGN46 (a trans golgi marker) (2 μg/ml), then washed and stainedwith a goat-anti-mouse IgG antibody-coupled to Alexafluor 594. Sampleswere washed then counter stained with 0.5 μg/ml DAPI. Coverslips weremounted on slides and viewed at m200-m1000 on an Olympus BH2fluorescence trinocular microscope using a HbO lamp and dichroicband-pass filter cubes. Images were captured to hard drive by a JenoptikGryphax camera and rendered using Adobe Photoshop software for contrastenhancement and edge sharpening.

Results

Extensive co-localization of Rab9 and FITC-NaPPS was observed in thecytoplasm of interphase and mitotic cells (FIG. 2 ). TGN46 stainingrevealed that NaPPS accumulated in endosomes close to the edges of thegolgi stacks (FIG. 3 ).

CONCLUSIONS

These data provide evidence of a potential mechanism by which NaPPSreduces viral infectivity and replication. NaPPS is likely to be aneffective treatment against SARS-COV-2 infection by specificallytargeting the autophagosome compartment and other golgi compartmentsused by the virus for assembly.

It will be understood that the invention disclosed and defined in thisspecification extends to all alternative combinations of two or more ofthe individual features mentioned or evident from the text or drawings.All of these different combinations constitute various alternativeaspects of the invention.

1-34. (canceled)
 35. A method of treating coronavirus infection or adisease or condition caused by or associated with coronavirus infection,the method comprising: providing an individual who is suspected ofhaving or of having had a coronavirus infection, administering to theindividual, a therapeutically effective amount of pentosan polysulfate(PPS) or a pharmaceutically acceptable salt thereof thereby treating orpreventing coronavirus infection or a disease or condition caused by orassociated with coronavirus infection in the individual.
 36. The methodof claim 35, wherein the disease or condition caused by or associatedwith coronavirus infection is a respiratory disease or condition, aninflammatory disease or condition, a cardiovascular disease or conditionor a gastrointestinal disease or condition.
 37. The method of claim 35,wherein the disease or condition caused by or associated withcoronavirus infection is cytokine-associated toxicity, includinghypercytokinemia.
 38. The method of claim 35, wherein the disease orcondition is characterised as a mild condition that does not requirehospitalisation.
 39. The method of claim 35, wherein the disease orcondition is characterised as severe and requiring hospitalisation. 40.The method of claim 35, wherein the individual does not display symptomsof coronavirus infection.
 41. A method of preventing cytokine-associatedtoxicity induced by coronavirus infection, the method comprising:providing an individual who been exposed to or has or is recovering froma coronavirus infection, administering to the individual, atherapeutically effective amount of pentosan polysulfate (PPS) or apharmaceutically acceptable salt thereof; thereby preventingcytokine-associated toxicity in the individual.
 42. The method accordingto claim 41, wherein the cytokine associated toxicity is characterisedby one or more of fever, hypotension, tachycardia, myalgia, headache andelevated levels of one or more cytokines selected from the groupconsisting of: IL-1B, IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-12, IL-13,IL-17 INFγ, TNF-α, granulocyte macrophage colony-stimulating factor. 43.The method of claim 35, wherein the method comprises treating one ormore of fever, hypotension, tachycardia, myalgia, headache orinappropriate cytokine release induced by coronavirus infection.
 44. Themethod of claim 35, wherein the pentosan polysulfate (PPS) isadministered prior to or after the onset of coronavirus infection. 45.The method of claim 35, wherein the PPS is administered prophylacticallyonce the individual has recovered from an initial infection withcoronavirus.
 46. A method of preventing or reducing the likelihood ofcoronavirus infection in an individual, the method comprising: providingan individual who is at risk of infection with a coronavirus;administering to the individual, a prophylactically effective amount ofpentosane polysulfate (PPS), or a pharmaceutically acceptable saltthereof, thereby preventing or reducing the likelihood of coronavirusinfection in an individual.
 47. The method of claim 46, wherein themethod reduces the likelihood of serious coronavirus infection.
 48. Themethod of claim 46, wherein the individual at risk is selected from:immunocompromised individuals (including an individual who has primaryor secondary immunodeficiency), an adult more than 60 years of age, achild younger than 2 years of age, healthcare workers, adults orchildren in close contact with a person(s) with confirmed or suspectedcoronavirus infection, and people with underlying medical conditionssuch as pulmonary infection, heart disease, obesity or diabetes.
 49. Themethod of claim 35, wherein the pentosan polysulfate (PPS) isadministered to the individual intravenously, subcutaneously, orally,intramuscularly, via gastric tube, intranasally or by inhalation. 50.The method of claim 35, wherein the pentosan polysulfate is provided asa salt selected from the group consisting of sodium pentosanpolysulfate, calcium pentosan polysulfate or magnesium pentosanpolysulfate.
 51. The method of claim 35, wherein the coronavirusinfection is an infection with SARS-CoV or SARS-CoV-2, or a mutated formor variant thereof, including but not limited to mutants D614G, S477N,20A.EU1, the Danish COVID-19 mink variant, the “UK” variant B
 1. 1. 7,the “South African” variant B.
 1. 351, the “Brazil” variant P.1 or the“Russian” variant B.
 1. 1.
 317. 52. The method of claim 35, wherein thecoronavirus infection is an infection with SARS-CoV-2 or variant ormutated form thereof.
 53. The method of claim 35, wherein the methodincludes further administering to the individual one or more of: acorticosteroid, an IL-6 inhibitor, a TNF-α inhibitor or a vasopressor.